041b0a81b0
# summary This MR fix `isBeforeInBlock` crash bug mentioned in https://github.com/llvm/llvm-project/issues/60909. Fixes #60909. # Trigger condition 1. A block only have one operation. 2. `block->isOpOrderValid()` is true, but `op->hasValidOrder()` is false. 3. call: `op->isBeforeInBlock(op)`, compared with op itself. Will crash on `assert(blockFront != blockBack && "expected more than one operation");` # Case study Simplified repro case in `mlir/test/Pass/scf2cf-print-liveness-crash.mlir` When put `-convert-scf-to-cf -test-print-liveness` together in one cmd line, the first pass will work normally and crash on the second pass. Details please refer https://github.com/llvm/llvm-project/issues/60909 # Solutions option1. in `isBeforeInBlock`, check if block only have one operation before step into `updateOrderIfNecessary`, if have only one, it must return false option2. in `isBeforeInBlock`, check if `this == other`, if true return false option3. fix `addNodeToList` logic I prefer option3: When a block contains only one operation and the user calls op->isBeforeInBlock(op), if block->isOpOrderValid() returns true, updateOrderIfNecessary is called. If op->hasValidOrder() is false, it will crash at the assertion assert(blockFront != blockBack && "expected more than one operation");. This behavior is abnormal and needs fixing. I discovered that after the first pass of `-convert-scf-to-cf`, there is a block with only one operation where the block order is valid but the operation order is invalid, leading to a crash when `-test-print-liveness` pass runs. --------- Co-authored-by: isaacw <isaacw@nvidia.com>
20 lines
761 B
MLIR
20 lines
761 B
MLIR
// RUN: mlir-opt %s -pass-pipeline="builtin.module(func.func(convert-scf-to-cf), func.func(test-print-liveness))"
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module {
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func.func @for_if_for(%arg0: index, %arg1: index, %arg2: index, %arg3: i1) {
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%cst = arith.constant dense<0.000000e+00> : tensor<128x32xf16>
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%0 = scf.for %arg4 = %arg0 to %arg1 step %arg2 iter_args(%arg5 = %cst) -> (tensor<128x32xf16>) {
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%1 = scf.if %arg3 -> (tensor<128x32xf16>) {
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scf.yield %arg5 : tensor<128x32xf16>
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} else {
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%2 = scf.for %arg6 = %arg0 to %arg1 step %arg2 iter_args(%arg7 = %arg5) -> (tensor<128x32xf16>) {
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scf.yield %arg7 : tensor<128x32xf16>
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}
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scf.yield %2 : tensor<128x32xf16>
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}
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scf.yield %1 : tensor<128x32xf16>
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}
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return
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}
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} |